Homelessness among unaccompanied youth is a hidden problem: the number of young people who experience homelessness each year is largely unknown. To improve the national response to youth homelessness, policymakers need better data on the magnitude of the problem. Youth Count! is a Federal interagency initiative that aims to improve counts of unaccompanied homeless youth. Nine communities participated in the initiative by expanding their annual homeless point-in-time efforts to increase coverage of homeless youth. Urban Institute conducted a process study of the initiative to identify promising practices that could be adapted and taken to scale to produce credible and useful data nationwide. (Author abstract)